Juniper Networks ERX-1440, ERX-1410, ERX-700, ERX-705 manual Redundancy Features ERX Edge Routers

Redundancy Features ERX Edge Routers

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If there is not enough space on the primary NVS card to create the synchronization reserve file, the synchronize command fails, and you see a warning message on the console. To resolve this issue, either delete unwanted files from the primary NVS card or replace the redundant NVS card with a higher-capacity NVS card.

Line Modules

The ERX system supports line module redundancy for several line modules. For details about which line modules support redundancy, see Appendix B, Module Specifications. In this scheme, an extra line access module in a group of identical line modules provides redundancy in case of line module failure. To use this feature, you need a:

•Spare line module

•Redundancy midplane

•Redundancy I/O module

A redundancy midplane may cover 2–6 slots. It provides additional connectivity that enables the spare line module to assume control of the I/O module associated with any failed line module in the redundancy group. The spare I/O module provides connectivity from the spare line module to the redundancy midplane.

The process by which the system switches to the spare line module is called switchover. When switchover occurs, the system:

1Breaks the connection between the primary I/O module and the primary line module.

2Connects the primary I/O module to the spare line module via the redundancy midplane and redundancy I/O module.

Protocol processing then takes place on the spare line module.

Figure 1-10shows the data flow when a spare line module becomes active.